The successful application of hypothermia to the surgery of the heart and brain is too well known to call for extensive documentation. Our own studies, which began with the extension of the safe time of occlusion of the abdominal aorta by means of hypothermia, reported in Part I,1have been extended to the specific devascularization of the liver. These latter experiments will be reported here. Resections of the liver in normothermic patients have been successfully accomplished by several surgeons. The largest series appears to be the four patients reported by Pack and colleagues.2The hazard of extensive blood loss, and of serious bile leakage owing to failure of complete bile-duct ligature in a sanguineous field, have kept these operations from gaining general acceptance. Bernhard and colleagues3have reported experiments similar to ours which indicate that a significant increase in safe operating time may be achieved by the